Diff: GPS.cpp

Revision:

0:697a7215cc10

Child:

1:0a034c2dbea6

diff -r 000000000000 -r 697a7215cc10 GPS.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/GPS.cpp	Sat Oct 06 22:41:59 2012 +0000
@@ -0,0 +1,73 @@
+#include "GPS.h"
+
+GPS::GPS(PinName tx, PinName rx) : _UltimateGps(tx, rx)
+{
+    _UltimateGps.baud(9600);
+}
+
+int GPS::parseData()
+{
+
+    while(1) {
+        getData();
+        if(sscanf(NEMA, "GPGGA, %*f, %*f, %*c, %*f, %*c, %d, %d, %*f, %f", &fixtype, &satellites, &altitude) >=1);
+        if(sscanf(NEMA, "GPRMC, %f, %c, %f, %c, %f, %c, %f, %f, %d", &time, &validity, &latitude, &ns, &longitude, &ew, &speed, &heading, &date) >=1) {
+            if(fixtype == '0') {
+                return 0;
+            }
+            if(fixtype == '1') {
+                fixname = "Positive";
+            }
+            if(fixtype == '2') {
+                fixname = "Differential";
+            }
+            if(ns =='S') {
+                latitude   *= -1.0;
+            }
+            if(ew =='W') {
+                longitude  *= -1.0;
+            }
+            float degrees = trunc(latitude / 100.0f);
+            float minutes = latitude - (degrees * 100.0f);
+            latitude = degrees + minutes / 60.0f;
+            degrees = trunc(longitude / 100.0f);
+            minutes = longitude - (degrees * 100.0f);
+            longitude = degrees + minutes / 60.0f;
+            return 1;
+        }
+    }
+}
+
+
+float GPS::trunc(float v)
+{
+    if(v < 0.0) {
+        v*= -1.0;
+        v = floor(v);
+        v*=-1.0;
+    } else {
+        v = floor(v);
+    }
+    return v;
+}
+
+void GPS::getData()
+{
+    while(_UltimateGps.getc() != '$');
+    for(int i=0; i<256; i++) {
+        NEMA[i] = _UltimateGps.getc();
+        if(NEMA[i] == '\r') {
+            NEMA[i] = 0;
+            return;
+        }
+    }
+    error("overflowed message limit");
+}
+
+void GPS::Init()
+{
+    _UltimateGps.printf("$PMTK220,1000*1F\r\n");
+    wait(1);
+    _UltimateGps.printf("$PMTK314,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*28\r\n");
+    wait(1);
+}